Devices including at least one adhesion layer and methods of forming adhesion layers

ABSTRACT

A device that includes a near field transducer (NFT), the NFT having a disc and a peg, and the peg having an air bearing surface thereof; and at least one adhesion layer positioned on at least the air bearing surface of the peg, the adhesion layer including one or more of platinum (Pt), iridium (Ir), ruthenium (Ru), rhodium (Rh), palladium (Pd), yttrium (Y), chromium (Cr), nickel (Ni), and scandium (Sc).

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.14/632,057, entitled DEVICES INCLUDING AT LEAST ONE ADHESION LAYER ANDMETHODS OF FORMING ADHESION LAYERS, filed Feb. 26, 2015, now issuing asU.S. Pat. No. 9,129,620 on Sep. 8, 2015, and which is a continuation ofU.S. application Ser. No. 14/313,574, entitled DEVICES INCLUDING ATLEAST ONE ADHESION LAYER AND METHODS OF FORMING ADHESION LAYERS, filedon Jun. 24, 2014, and issued as U.S. Pat. No. 8,971,161 on Mar. 3, 2015,and claims priority to U.S. Provisional Application No. 61/838,394,entitled ADHESION LAYER FOR NEAR FIELD TRANSDUCERS AND STRUCTURESCONTAINING THE SAME, filed on Jun. 24, 2013, and 61/984,915 entitledMETHODS OF FORMING NEAR FIELD TRANSDUCERS (NFTS) USING ION IMPLANTATION,filed on Apr. 28, 2014, the disclosures of which are incorporated hereinby reference thereto.

SUMMARY

Disclosed are devices that include a near field transducer (NFT), theNFT having a disc and a peg, and the peg having an air bearing surface;and at least one adhesion layer positioned on the air bearing surface ofthe peg, the adhesion layer including one or more of the following:tungsten (W), molybdenum (Mo), chromium (Cr), silicon (Si), nickel (Ni),tantalum (Ta), titanium (Ti), yttrium (Y), vanadium (V), magnesium (Mg),cobalt (Co), tin (Sn), niobium (Nb), hafnium (Hf), and combinationsthereof tantalum oxide, titanium oxide, tin oxide, indium oxide, andcombinations thereof vanadium carbide (VC), tungsten carbide (WC),titanium carbide (TiC), chromium carbide (CrC), cobalt carbide (CoC),nickel carbide (NiC), yttrium carbide (YC), molybdenum carbide (MoC),and combinations thereof and titanium nitride (TiN), zirconium nitride(ZrN), hafnium nitride (HfN), and combinations thereof.

Also disclosed are devices that include an energy source; a near fieldtransducer (NFT) configured to receive energy from the energy source,the NFT having a disc and a peg, and the peg having an air bearingsurface; and at least one adhesion layer positioned on at least the airbearing surface of the peg, the adhesion layer comprising one or more ofthe following: rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt),ruthenium (Ru), technetium (Tc), rhodium (Rh), palladium (Pd), beryllium(Be), aluminum (Al), manganese (Mn), indium (In), boron (B), andcombinations thereof; beryllium oxide (BeO), silicon oxide (SiO), ironoxide (FeO), zirconium oxide (ZrO), manganese oxide (MnO), cadmium oxide(CdO), magnesium oxide (MgO), hafnium oxide (HfO), and combinationsthereof; tantalum carbide (TaC), uranium carbide (UC), hafnium carbide(HfC), zirconium carbide (ZrC), scandium carbide (ScC), manganesecarbide (MnC), iron carbide (FeC), niobium carbide (NbC), technetiumcarbide (TcC), rhenium carbide (ReC), and combinations thereof; andchromium nitride (CrN), boron nitride (BN), and combinations thereof.

The above summary of the present disclosure is not intended to describeeach disclosed embodiment or every implementation of the presentdisclosure. The description that follows more particularly exemplifiesillustrative embodiments. In several places throughout the application,guidance is provided through lists of examples, which examples can beused in various combinations. In each instance, the recited list servesonly as a representative group and should not be interpreted as anexclusive list.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a magnetic disc drive that can includeHAMR devices.

FIG. 2 is a cross sectional view of a perpendicular HAMR magneticrecording head and of an associated recording medium.

FIGS. 3A and 3B are a perspective views of an illustrative NFT (FIG. 3A)and the peg thereof (FIG. 3B).

FIGS. 4A to 4D show surface energies of 3d metals (FIG. 4A), 5d metals(FIG. 4B), 4d metals (FIG. 4C), and non-transition metals (FIG. 4D).

FIG. 5 is a graph showing surface free energies of various nitridecoatings at 20° C.

FIGS. 6A and 6B are scanning electron microscope (SEM) images of asample including a 25 Å Ir adhesion layer (FIG. 6A) and TaO layer forcomparison (FIG. 6B), both annealed at 400° C. for 48 hours.

The figures are not necessarily to scale. Like numbers used in thefigures refer to like components. However, it will be understood thatthe use of a number to refer to a component in a given figure is notintended to limit the component in another figure labeled with the samenumber.

DETAILED DESCRIPTION

Heat assisted magnetic recording (referred to through as HAMR) utilizesradiation, for example from a laser, to heat media to a temperatureabove its curie temperature, enabling magnetic recording. In order todeliver the radiation, e.g., a laser beam, to a small area (on the orderof 20 to 50 nm for example) of the medium, a NFT is utilized. During amagnetic recording operation, the NFT absorbs energy from a laser andfocuses it to a very small area; this can cause the temperature of theNFT to increase. The temperature of the NFT can be elevated up to about400° C. or more.

In some embodiments, a NFT can include a small peg and a large disk. Thevery high temperatures that the NFT reaches during operation can lead todiffusion of the material of the NFT (for example gold) from the peg andtowards the disk. This can lead to deformation and recession of the peg,which can lead to failure of the NFT and the entire head.

Disclosed devices include one or more layers adjacent one or moresurfaces of the peg of the NFT to increase or improve adhesion of thepeg material to the surrounding materials or structures within thedevice. If the peg is better adhered to the surrounding materials orstructures, it will be less likely to deform and/or recess.

FIG. 1 is a perspective view of disc drive 10 including an actuationsystem for positioning slider 12 over track 14 of magnetic medium 16.The particular configuration of disc drive 10 is shown for ease ofdescription and is not intended to limit the scope of the presentdisclosure in any way. Disc drive 10 includes voice coil motor 18arranged to rotate actuator arm 20 on a spindle around axis 22. Loadbeam 24 is connected to actuator arm 20 at head mounting block 26.Suspension 28 is connected to an end of load beam 24 and slider 12 isattached to suspension 28. Magnetic medium 16 rotates around an axis 30,so that the windage is encountered by slider 12 to keep it aloft a smalldistance above the surface of magnetic medium 16. Each track 14 ofmagnetic medium 16 is formatted with an array of data storage cells forstoring data. Slider 12 carries a magnetic device or transducer (notshown in FIG. 1) for reading and/or writing data on tracks 14 ofmagnetic medium 16. The magnetic transducer utilizes additionalelectromagnetic energy to heat the surface of medium 16 to facilitaterecording by a process termed heat assisted magnetic recording (HAMR).

A HAMR transducer includes a magnetic writer for generating a magneticfield to write to a magnetic medium (e.g. magnetic medium 16) and anoptical device to heat a portion of the magnetic medium proximate to thewrite field. FIG. 2 is a cross sectional view of a portion of a magneticdevice, for example a HAMR magnetic device 40 and a portion ofassociated magnetic storage medium 42. HAMR magnetic device 40 includeswrite pole 44 and return pole 46 coupled by pedestal 48. Coil 50comprising conductors 52 and 54 encircles the pedestal and is supportedby an insulator 56. As shown, magnetic storage medium 42 is aperpendicular magnetic medium comprising magnetically hard storage layer62 and soft magnetic underlayer 64 but can be other forms of media, suchas patterned media. A current in the coil induces a magnetic field inthe pedestal and the poles. Magnetic flux 58 exits the recording head atair bearing surface (ABS) 60 and is used to change the magnetization ofportions of magnetically hard layer 62 of storage medium 42 enclosedwithin region 58. Near field transducer 66 is positioned adjacent thewrite pole 44 proximate air bearing surface 60. Near field transducer 66is coupled to waveguide 68 that receives an electromagnetic wave from anenergy source such as a laser. An electric field at the end of nearfield transducer 66 is used to heat a portion 69 of magnetically hardlayer 62 to lower the coercivity so that the magnetic field from thewrite pole can affect the magnetization of the storage medium.

Devices disclosed herein can also include other structures. Devicesdisclosed herein can be incorporated into larger devices. For example,sliders can include devices as disclosed herein. Exemplary sliders caninclude a slider body that has a leading edge, a trailing edge, and anair bearing surface. The write pole, read pole, optical near fieldtransducer and contact pad (and optional heat sink) can then be locatedon (or in) the slider body. Such exemplary sliders can be attached to asuspension which can be incorporated into a disc drive for example. Itshould also be noted that disclosed devices can be utilized in systemsother than disc drives such as that depicted in FIG. 1.

FIGS. 3A and 3B show an example of the peg and disc of a peg and disctype NFT, and FIG. 3B shows a closer view of only the peg of the peg anddisc type NFT shown in FIG. 3A. The NFT in FIG. 3A includes a peg 305and a disc 310. The peg 305 shown in FIGS. 3A and 3B includes fivesurfaces that are not in contact with the disc 310, an air bearingsurface 306, a first surface 307, a second surface 309, a third surface308, and a fourth surface 311.

In some embodiments, the second surface 309 and the first surface 307are facing the pole and core respectively. In some embodiments, thethird surface 308 and the fourth surface 311 are not facing the pole orthe core. More specifically, the third surface 308 would be located infront of the paper on which FIG. 2 is depicted and the fourth surface311 would be located behind the paper on which FIG. 2 is depicted. Insome embodiments, the second surface 309 can also be referred to as theNFT-pole surface which faces a NFT-pole space, which can be referred toas a NPS (not shown herein). In some embodiments, the first surface 307can also be referred to as the NFT-core surface, which faces a NFT-corespace, which can be referred to as CNS (not shown herein). In someembodiments, the third surface 308 can also be described as the surfacewhich faces the left side of a device, in some embodiments; a left solidimmersion mirror can be located there. In some embodiments, the fourthsurface 311 can also be described as the surface which faces the rightside of a device, in some embodiments; a right solid immersion mirrorcan be located there.

Disclosed devices can include one or more adhesion layers located on oneor more surfaces of a NFT. In some embodiments, disclosed devices caninclude one or more adhesion layers located on one or more surfaces of apeg of a NFT. In some embodiments, disclosed devices can includeadhesion layers located on two or more surfaces of a peg of a NFT. Insome embodiments, disclosed devices can include adhesion layers locatedon three or more surfaces of a peg of a NFT. In some embodiments,disclosed devices can include adhesion layers located on four or moresurfaces of a peg of a NFT. In some embodiments, disclosed devices caninclude adhesion layers located on all five surfaces of a peg of a NFT.In some embodiments disclosed devices can include adhesion layerslocated on each of the first surface 307, the second surface 309, thethird surface 308, and the fourth surface 311. Adhesion layers ondifferent surfaces of the peg could have different materials. In someembodiments, the adhesion layer on one or more surfaces could bedifferent in order to reduce the optical penalty.

The material of the adhesion layer can be selected based, at least inpart, on properties of the materials that will surround the adhesionlayer. For example, the material of the adhesion layer can be selectedbased, at least in part, on properties of the material of the NFT, forexample the peg. In some embodiments, the NFT can be made of gold (Au)or gold containing materials for example.

At operating temperatures (relatively high, for example 400° C. orhigher) gold (for example) can de-bond from surrounding surfaces (forexample the CNS, the NPS, or the head overcoat (HOC) on the ABS) due tolow adhesion strengths between the gold and surrounding materials.

When the peg de-bonds from the surfaces surrounding it, the gold atomsat the peg tend to diffuse toward the disk because of the low meltingpoint of gold and in order to reduce more unfavorable (e.g., larger)surface area/volume ratio of the peg as compared to the disk. When twosurfaces (A and B, for example) separate from each other, two newsurfaces will replace the A/B interface. The total energy change ofseparation can then be given by

Δγ=(γA+γB)−γInterface

where γA and γB are the surface energy of surfaces A and B respectively,and γInterface is the interface energy of A and B. The larger Δγ is, thebetter the adhesion of the two materials or surfaces. In order toincrease adhesion between two surfaces, for example the NFT material(e.g., gold or gold containing material) and a surrounding material, thesurface energy of the surrounding material should be increased and theinterface energy of the surrounding material with gold should bedecreased.

Interface energy (γInterface) can be described as the excess energy perunit area of a system due to the appearance of the interface. Interfaceenergy originates from the change in the interfacial atomic chemicalbonding and the structure/strain at the interface. The interface energycan also be characterized as including the chemical interface energy andthe structural interface energy. In some embodiments, reducing theinterface energy between the NFT material and an adhesion layercontaining a particular material can be accomplished by utilizingmaterials for the adhesion layer that have similar atomic chemicalbonding and atomic radii to the NFT material.

Materials that can be utilized in adhesion layers may have relativelyhigh surface energies and relatively low interface energies with gold(for example). Illustrative materials that can be utilized in adhesionlayers can include, for example metals, oxides, nitrides, or carbidesthat have relatively high surface energies and relatively low interfaceenergies with gold (for example).

In some embodiments, adhesion layers (located on one or more surfaces ofa NFT, for example a peg of a NFT) can include one or more metals. Insome embodiments, the metal can include specific illustrative metalssuch as for example rhenium (Re), osmium (Os), iridium (Ir), platinum(Pt), ruthenium (Ru), technetium (Tc), rhodium (Rh), palladium (Pd),beryllium (Be), aluminum (Al), manganese (Mn), indium (In), boron (B),or combinations thereof. In some embodiments, the metal can includespecific illustrative metals such as for example Pt, Ir, Al, Rh, Ru, Pd,or combinations thereof. In some embodiments, the metal can includespecific illustrative metals such as for example Pt, Ir, Al, orcombinations thereof. In some embodiments, the metal can includespecific illustrative metals such as for example Pt. In someembodiments, the metal can include specific illustrative metals such asfor example Ir. In some embodiments, the metal can include a metal thathas a relatively high resistance to oxidation so that the adhesion layeris not oxidized during use of the NFT. In some such embodiments, themetal can include specific illustrative metals such as for example Ir,Pt, Pd, Ru, Rh, Re, Nb, Os, Al, B, or combinations thereof.

In some embodiments, adhesion layers (located on one or more surfaces ofa NFT, for example a peg of a NFT) can include one or more metals. Insome embodiments, the metal can include specific illustrative metalssuch as for example tungsten (W), molybdenum (Mo), chromium (Cr),silicon (Si), nickel (Ni), tantalum (Ta), titanium (Ti), yttrium (Y),vanadium (V), magnesium (Mg), cobalt (Co), tin (Sn), niobium (Nb),hafnium (Hf), or combinations thereof. In some embodiments, the metalcan include specific illustrative metals such as for example Cr, Ni, Sn,or combinations thereof. In some embodiments, the metal can includespecific illustrative metals such as for example Cr, Sn, or combinationsthereof. In some embodiments, the metal can include a metal that has arelatively high resistance to oxidation so that the adhesion layer isnot oxidized during use of the NFT. In some such embodiments, the metalcan include specific illustrative metals such as for example W, Ti, Cr,Si, Ni, or combinations thereof.

In some embodiments, adhesion layers (located on one or more surfaces ofa NFT, for example a peg of a NFT) can include one or more metals. Insome embodiments, the metal can include specific illustrative metalssuch as for example Re, Os, Ir, Pt, Hf, Ta, Ru, Tc, Nb, Rh, Pd, Be, Al,Mn, In, W, Mo, Cr, Si, Ni, Ti, Y, V, Mg, Co, Sn, or combinationsthereof. In some such embodiments, the metal can include specificillustrative metals such as for example Ir, Pt, Pd, Nb, Ru, Re, Ta, Os,Al, B, W, Ti, Cr, Si, Ni, or combinations thereof. In some embodiments,the metal can include specific illustrative metals such as for examplePt, Ir, Al, Cr, Ni, Sn, or combinations thereof. In some embodiments,the metal can include specific illustrative metals such as for examplePt, Ir, Cr, Sn, or some combinations thereof. In some embodiments, themetal can include a metal that has a relatively high resistance tooxidation so that the adhesion layer is not oxidized during use of theNFT. In some such embodiments, the metal can include specificillustrative metals such as for example Ir, Pt, Pd, Nb, Ru, Re, Ta, Nb,Os, Al, B, W, Ti, Cr, Si, Ni, or combinations thereof.

FIG. 4A shows calculated surface energies (J/m²) as a function ofvalence for the fcc (111) surfaces of the 3d metals in the solidsquares; structure-independent surface energies derived from the surfacetension of the liquid metals of the 3d metals in the open circles; andthe solid line is a guide to the eye while the dashed line connects someof the results. FIG. 4B shows calculated surface energies for the fcc(111) surfaces of the 5d metals in the solids squares;structure-independent surface energies derived from the surface tensionof the liquid metals of the 5d metals in the open circles; and the solidline is a guide to the eye. FIG. 4C shows calculated surface energies(J/m²) as a function of valence for the fcc (111) surfaces of the 4dmetals in the solid squares; structure-independent surface energiesderived from the surface tension of the liquid metals of the 4d metalsin the open circles; and the solid line is a guide to the eye while thedashed line connects some of the results. FIG. 4D shows calculatedsurface energies (J/m²) as a function of valence for the fcc (111)surfaces of the non-transition metals in the solid squares;structure-independent surface energies derived from the surface tensionof the liquid metals of the non-transition metals in the open circles;and the solid line is a guide to the eye while the dashed line connectssome of the results.

In some embodiments, adhesion layers (located on one or more surfaces ofa NFT, for example a peg of a NFT) can include one or more oxides. Insome embodiments, the oxide can include specific illustrative oxidessuch as for example, beryllium oxide (BeO), silicon oxide (SiO), ironoxide (FeO), zirconium oxide (ZrO), manganese oxide (MnO), cadmium oxide(CdO), magnesium oxide (MgO), hafnium oxide (HfO), or some combinationthereof. In some embodiments, the oxide can include specificillustrative oxides such as for example, tantalum oxide (TaO), titaniumoxide (TiO), tin oxide (SnO), indium oxide (InO), or some combinationthereof. In some embodiments, the oxide can include specificillustrative oxides such as for example, beryllium oxide (BeO), siliconoxide (SiO), iron oxide (FeO), aluminum oxide (AlO), titanium oxide(TiO), zirconium oxide (ZrO), tantalum oxide (TaO), manganese oxide(MnO), cadmium oxide (CdO), tin oxide (SnO), indium oxide (InO), indiumtin oxide (ITO), or some combination thereof. It should be noted thatoxides can include any stoichiometry including the particular notedelement and oxygen. For example silicon oxide includes both silicondioxide (SiO₂) and silicon monoxide (SiO).

Table 1 below shows surface energies and transformation energiesrelative to bulk stable polymorph for several oxides

TABLE 1 Surface Energy Transformation energy Oxide (J/m²) (kJ/mol)α-Al₂O₃ 2.6 ± 0.2 0 γ-Al₂O₃ 1.7 ± 0.1 13.4 _(±) 2.0  AlOOH (bochmite)0.5 ± 0.1 −17 _(±) 1  TiO₂ (rutile) 2.2 ± 0.2 0 TiO₂ (brookite) 1.0 ±0.1 0.7 _(±) 0.4 TiO₂ (anatase) 0.4 ± 0.1 2.6 _(±) 0.4 ZrO₂ (monoclinic)6.5 ± 0.2 0 ZrO₂ (tetragonal)  2.1 ± 0.05 9.5 ± 0.4 ZrO₂ (amorphous) 0.5 ± 0.05 34 ± 4  Zeolitic silicas 0.09 ± 0.01  7-15

Table 2 below shows calculated surface energies of (100) face of MOoxides at 0° K.

TABLE 2 Oxide Surface Energy (J/m²) MgO 1.362 MgO 1.459 CaO 1.032 BaO0.641 MnO 1.247 CdO 1.044

Table 3 below shows surface energies of MO oxides (crystal systemunspecified) at 0° K.

TABLE 3 Oxide Surface Energy (J/m²) MgO 1.090 FeO 1.060 MnO 1.010 CaO0.820 SrO 0.700 BaO 0.605 BeO >1.420 CdO 0.530 ZnO 0.600 PbO 0.250

Table 4 below shows surface energies of MO₂ oxides (crystal systemunspecified) at 0° K.

TABLE 4 Oxide Surface Energy (J/m²) ZrO₂ 0.800 ± 20% UO₂ 0.640 ± 20%ThO₂ 0.530 ± 20%

In some embodiments, adhesion layers (located on one or more surfaces ofa NFT, for example a peg of a NFT) can include one or more carbides. Insome embodiments, the carbide can include specific illustrative carbidessuch as for example, tantalum carbide (TaC), uranium carbide (UC),hafnium carbide (HfC), zirconium carbide (ZrC), scandium carbide (ScC),manganese carbide (MnC), iron carbide (FeC), niobium carbide (NbC),technetium carbide (TcC), rhenium carbide (ReC), or some combinationthereof. In some embodiments, the carbide can include specificillustrative carbides such as for example, vanadium carbide (VC),tungsten carbide (WC), titanium carbide (TiC), chromium carbide (CrC),cobalt carbide (CoC), nickel carbide (NiC), yttrium carbide (YC),molybdenum carbide (MoC), or some combination thereof. In someembodiments, the carbide can include specific illustrative carbides suchas for example, vanadium carbide (VC), tantalum carbide (TaC), titaniumcarbide (TiC), uranium carbide (UC), tungsten carbide (WC), hafniumcarbide (HfC), zirconium carbide (ZrC), chromium carbide (CrC), scandiumcarbide (ScC), manganese carbide (MnC), iron carbide (FeC), cobaltcarbide (CoC), nickel carbide (NiC), yttrium carbide (YC), niobiumcarbide (NbC), molybdenum carbide (MoC), technetium carbide (TcC),rhenium carbide (ReC), or some combination thereof.

Table 5 below shows surface energies of monocarbides (crystal systemunspecified) at 1100° C.

TABLE 5 Carbide Surface Energy (J/m²) ZrC 0.80 ± 0.25 UC 1.0 ± 0.3 TiC1.19 ± 0.35 TaC 1.29 ± 0.39 VC 1.675 ± 0.5 

Table 6 below shows surface energies E_(S) (in both eV/atom and J/m2)and theoretical and experimental work functions Φ (in eV) for the 3d,4d, and 5d transition metal carbides calculated using the linear muffintin orbital basis atomic sphere approximation (LMTO-ASA) technique.

TABLE 6 Carbide E_(S) [eV] E_(S) [J/m²] Φ^(the) [eV] Φ^(exp) [eV] SeC0.67 1.88 4.94 — TiC 0.83 2.73 4.94 3.8 4.1 VC 0.77 2.75 5.02 4.3 CrC0.71 2.67 5.56 — MnC 0.70 2.74 5.76 — FeC 0.71 2.87 5.83 — CoC 0.72 2.916.13 — NiC 0.45 1.83 6.06 — CuC 0.42 1.57 5.66 — YC 0.65 2.01 4.10 — ZrC0.86 2.66 4.45 — NbC 0.87 2.81 4.45 4.1 MoC 0.77 2.57 5.10 3.5 TeC 0.692.27 5.53 — RhC 0.68 2.21 5.72 — RuC 0.69 2.24 5.98 — PdC 0.47 1.50 6.09— AgC 0.39 1.14 5.64 — LaC 0.70 1.94 4.64 — HfC 0.90 2.87 4.45 4.6 TaC0.88 2.99 4.36 4.3 WC 0.77 2.64 5.16 — ReC 0.66 2.14 5.63 — OsC 0.621.93 5.87 — IrC 0.59 1.75 5.87 — PtC 0.49 1.41 6.28 — AuC 0.35 0.93 5.79—

In some embodiments, adhesion layers (located on one or more surfaces ofa NFT, for example a peg of a NFT) can include one or more nitrides. Insome embodiments, the nitride can include specific illustrative nitridessuch as for example, chromium nitride (CrN), boron nitride (BN), or somecombination thereof. In some embodiments, the nitride can includespecific illustrative nitrides such as for example, titanium nitride(TiN), zirconium nitride (ZrN), hafnium nitride (HfN), or somecombination thereof. In some embodiments, the nitride can includespecific illustrative nitrides such as for example, chromium nitride(CrN), boron nitride (BN), titanium nitride (TiN), zirconium nitride(ZrN), hafnium nitride (HfN), or some combination thereof.

FIG. 5 is a graph showing surface free energies of various coatings at20° C. The surface free energy is divided into polar (gray mode on top)and dispersion (white mode on bottom) components.

Disclosed adhesion layers can have various thicknesses. The thickness ofan adhesion layer can refer to the average thickness of the adhesionlayer. In some embodiments, a disclosed adhesion layer can have athickness that is at least 0.1 nm (1 Å), in some embodiments at least0.2 nm (2 Å), or in some embodiments at least 1 nm (10 Å). In someembodiments, a disclosed adhesion layer can have a thickness that is notgreater than 100 nm (1000 Å), in some embodiments not greater than 40 nm(400 Å), in some embodiments, not greater than 5 nm (50 Å), or in someembodiments not greater than 3.5 nm (35 Å). The thickness (e.g., theaverage thickness) of an adhesion layer can be measured using, forexample, transmission electron microscopy (TEM), X-ray reflectivity(XRR), or x-ray photoelectron spectroscopy (XPS). The thickness can bedetermined using calibration from standard samples having knownthicknesses, for example.

One of skill in the art, having read this specification will understandthat NFT types other than peg and disk (also referred to as “lollipop”type NFTs) could be utilized herein. For example plasmonic gap type NFTsand peg only NFTs can also be utilized. In some embodiments, variousmaterials including, for example, gold (Au), silver (Ag), copper (Cu),alloys thereof, or other materials can be utilized to form a NFT. Insome embodiments, the NFT can also be made of materials listed in U.S.Patent Publication No. 2013/0286799, U.S. Pat. No. 8,427,925, and U.S.patent application Ser. No. 13/923,925 entitled MAGNETIC DEVICESINCLUDING FILM STRUCTURES, filed on Jun. 21, 2013, and Ser. No.14/062,651 entitled RECORDING HEADS INCLUDING NFT AND HEATSINK, filed onOct. 24, 2013, the disclosures of which are incorporated herein byreference thereto.

In some embodiments, materials that can be utilized for adhesion layerscan be those that provide acceptable levels of NFT coupling efficiencyloss. Such materials can generally have relatively high indices ofrefraction (n). The presence of a non-plasmonic material layer, e.g., adisclosed adhesion layer in some embodiments, at the interface of theNFT material and the cladding material layer can “dampen” the ability ofthat interface to support surface plasmons, which can result in weakerelectric field emission from the NFT. Such materials may also haverelatively favorable k values. In some embodiments, materials that aremore highly detrimental from an optical standpoint can be utilized atrelatively smaller thicknesses, for example.

Methods of making devices including disclosed adhesion layers can varydepending on the location of the adhesion layer. In embodiments whereone or more adhesion layers are being utilized on the first surface 307,the third surface 308, the fourth surface 311, or any combinationthereof, the adhesion layer(s) can be deposited, then the NFT materialcan be deposited, followed by the cladding or dielectric material. Theadhesion layer(s) then affects adhesion between the underlyingdielectric material (for example the cladding layers or dielectriclayers) and the NFT. In embodiments where an adhesion layer is utilizedon the second surface 309, the adhesion layer material can be depositedon the NFT material after it is deposited, for example in a trench(either lined with a disclosed adhesion layer material or not). Theadhesion layer on the second surface 309 then affects adhesion betweenthe NFT material and the overlying dielectric material (for example thetop cladding layer). In some embodiments, an adhesion layer material canbe deposited on a NFT material layer. This structure can then be trimmedin order to form a peg (from the NFT material layer) with an adhesionlayer on the first surface 307 of the peg. Next, an adhesion layer canbe formed on the third surface 308, the fourth surface 311 and thesecond surface 309. Excess adhesion layer material can then optionallybe removed from the structure.

Illustrative processes for forming disclosed adhesion layers can includefor example, deposition methods such as chemical vapor deposition (CVD),physical vapor deposition (PVD), atomic layer deposition (ALD), plating(e.g., electroplating), sputtering methods, cathodic arc depositionmethods, ion implantation method and evaporative methods.

Processes to form the adhesion layer could be easily integrated into theoverall manufacturing process of the device. Overall, the use ofdisclosed adhesion layers would decrease or eliminate yield loss due todelamination of the NFT and contribute to increased NFT lifetime duringthe operation of the magnetic device with very little effect on currentformation processes for the device.

In some embodiments, an adhesion layer can be formed using ionimplantation. Such methods of forming adhesion layers can includeimplanting one or more elements into a layer that will ultimately belocated immediately below the NFT (which can be made from gold (Au),silver (Ag), copper (Cu), aluminum (Al), rhodium (Rh), rhenium (Re),alloys (binary or ternary for example) thereof, or combinations thereof,for example). In some embodiments, such layers can be dielectricmaterials. Illustrative dielectric materials can include alumina,yttria, zirconia, titania, niobia, or combinations thereof, for example.For example, an adhesion layer can be formed by implanting one or moreelements into the dielectric material that will ultimately form the coreto NFT space (CNS). Other portions of a device, which will ultimately belocated adjacent other surfaces of the NFT can also be implanted withone or more elements to form disclosed adhesion layers. In someembodiments adhesion layers can be formed by implanting elements intothe dielectric material that forms the pole to NFT space (NPS), thedielectric material that forms cladding of an adjacent waveguide, or anycombination thereof.

Implanting one or more elements into dielectric material that willultimately be adjacent the NFT is thought, but not relied upon, tosurface modify the dielectric layer thereby providing an improvedwettability and metal adhesion to the dielectric. Implantation of one ormore elements into adjacent dielectric materials could serve to modifythe surface nanotopology so as to influence and change the growth modeof the film from three dimensional islanded growth to planar growth.Alternatively, the implanted ions themselves could be chosen in order toinfluence the kinetics of a nucleation and growth process beingdeposited thereon, thereby forming planar, denser NFT films. Theelements to implant could be chosen so that they could modify thesurface energy of the dielectric surface for deposition. The elements,when having such effects could be considered surfactants ions, catalystions, or both for example. The elements to implant could also oralternatively be chosen to poison or block certain sites of nucleationand growth of the NFT layer.

The element or elements to implant, which will in effect be implanted asions can vary and can be chosen based on considerations mentioned aboveas well as others. In some embodiments, implanted elements can bemetallic elements, inert gasses, halogens, other types of elements, orcombinations thereof, for example. Illustrative elements can includealuminum (Al), iron (Fe), silicon (Si), bismuth (Bi), lead (Pb), tin(Sn), cobalt (Co), ruthenium (Ru), nickel (Ni), germanium (Ge), antimony(Sb), arsenic (As), gallium (Ga), sodium (Na), potassium (K), selenium(Se), gold (Au), silver (Ag), copper (Cu), rhodium (Rh), indium (In),tellurium (Te), or combinations thereof, for example. Illustrativeelements can include argon (Ar), krypton (Kr), xenon (Xe), neon (Ne), orcombinations thereof for example. Illustrative elements can includechlorine (Cl), iodine (I), or combinations thereof for example.Illustrative elements can include oxygen (O), phosphorus (P), carbon(C), nitrogen (N), sulfur (S), or combinations thereof for example. Someillustrative elements, for example inert gasses can also be used forsurface bombardment, nanotopolgy creation, or combinations thereof forexample. As discussed above, the particular element or elements chosencan be chosen, based at least in part, to improve film density, changelocal surface wetting angles advantageously, encourage two dimensionalplanar growth, advantageously alter the sticking coefficient of the NFTlayer (e.g., metal layer) to the dielectric layer, act as selectivecatalysts or preferred sites for the growth of the NFT material, promoteuniform nucleation, improve interfacial strength, high temperaturestability, or combinations thereof. In some embodiments where the NFTmaterial will include gold (Au), the dielectric material, e.g., the CNS,can be implanted with Au ions.

In some embodiments more than one element can be implanted into thedielectric material in order to modify the surface upon with the NFTmaterial will be deposited. In some embodiments, the at least twospecies may react with each other, they may react with the dielectricmaterial surface, they may react with the NFT material while it is beingdeposited or once it is deposited, or some combination thereof. Thereaction of the one or more elements may serve to improve the density ofthe NFT material deposited, improve the interfacial strength, or somecombination thereof.

The concentration of implanted element(s) can vary and need not be thesame across the implantation surface or into the implantation surface.In some embodiments, the concentration of the implanted element(s) canbe advantageously modified in the vicinity of the NFT growth surface. Insome embodiments, the elements can have a concentration profile into thedielectric material. In some embodiments, the concentration profile ofthe implanted element(s) can be tailored so as to cause a gradedcomposition profile in the dielectric material. In some embodiments,graded compositions can be advantageously used to modify the stressstate in the film and the overall device. In some embodiments, theconcentration of the element(s) can be not less than 10 ppm (0.001atomic percent or at %), or in some embodiments not less than 100 ppm(0.01 at %). In some embodiments, the concentration of the element(s)can be not greater than 10 at %, in some embodiments not greater than 5at %, or in some embodiments not greater than 2 at %.

The energy of the implanted element(s) or ion(s) as they would beimplanted will control the penetration depth of the element into thedielectric material. Sub surface penetration of the species into thefirst few nanometers (nm) of the dielectric layer (e.g., the CNS) mayserve to anchor a NFT layer formed thereon, thereby improving theinterfacial strength and robustness.

The at least one element can be implanted into the dielectric materialusing various types of systems. In some embodiments beam line implantscan be utilized, while in some embodiments plasma immersion implants canbe utilized. In embodiments where a beam line implant is utilized, theion beam can be positioned at an angle normal (90 degrees) to the samplesurface, or it can be incident at an angle ranging from 1 degree to 90degrees, for example. The sample can be stationary during theimplantation or it can be rotated at a fixed or variable rate of speedduring the implant. Implantation (and other optional steps) can becarried out on planar surfaces, on sloped or contoured surfaces, onsurfaces with retrograde wall angles, or any combination thereof.

In some embodiments, implantation of one or more elements into adielectric material may optionally be combined with other treatments ofthe dielectric material prior to deposition of a NFT material. In someembodiments, such other optional processes can include, thermaltreatments (e.g., annealing), chemical treatments, gaseous treatments,or some combination thereof. In some embodiments, implantation of one ormore elements may be interspersed with such other optional treatments.In some embodiments, implantation of one or more elements into adielectric material may optionally be combined with one or more etchingsteps prior to deposition of the NFT material. Such optional etch stepsmay be performed after an ion implantation step in order to truncate thedielectric surface where the Rp value is the highest (Rp or theprojected range is the average distance a group of implanted ions travelinto the surface). The optional etching step can be advantageouslyfollowed by deposition of the NFT material, deposition of a metal (thatis not the NFT material), deposition of a seedlayer, deposition of adielectric layer, or any combination thereof. In some embodiments, anoptional seedlayer material can be ion implanted into the dielectricmaterial. Element(s) implantation steps may also optionally be followedby thermal treatments, UV treatments, heat treatments, chemicaltreatments, or any combination thereof prior to, during, or bothsubsequent metal deposition thereon.

In some embodiments, implantation of the dielectric layer can befollowed by deposition of a NFT material and formation of at least aportion of a NFT from the deposited NFT material. Formation of at leasta portion of a NFT can include formation of at least a peg, for example.Formation of at least a portion of a NFT can include various processesincluding for example patterning and removal steps. In some embodimentsphotolithography processes, etching steps, or combinations thereof canbe utilized.

In some embodiments, implantation of one or more elements into thedielectric material can be followed by deposition of a partial NFTmaterial layer. The partial NFT material layer can have a thickness thatis not less than 0.1 nm and in some embodiments may have a thicknessthat is not greater than 20 nm. The partial NFT material layer can thenbe implanted with an element that could serve to advantageously improvethe film densification or enhance the interfacial strength of theinterface (e.g., the CNS/NFT interface). Such a species may have anaffinity for both the NFT material and the dielectric material (e.g.,the CNS). A specific example of such a material could include sulfur(S), which will preferentially bond to metal atoms, such as gold forexample. The implantation process and the partial NFT material layerdeposition process could be carried out alternatively in repeatedsequence so as to create a layered or a graded structure.

Further information can also be found in United States patentapplication entitled “MATERIALS FOR NEAR FIELD TRANSDUCERS AND NEARFIELD TRANSDUCERS CONTAINING SAME” having attorney docket number430.18020010, having as inventors Sethuraman Jayashankar and MichaelKautzky, the entire disclosure of which is incorporated herein byreference thereto.

While the present disclosure is not so limited, an appreciation ofvarious aspects of the disclosure will be gained through a discussion ofthe examples provided below.

Examples

On the ABS surface of a HAMR head (that included a SiO₂ CNS, an Au pegof a NFT, and a SiO₂ NPS), a 25 Å thick Ir layer was deposited usingmagnetron sputtering and on top of that surface, a 20 Å layer of diamondlike carbon (DLC) film was deposited using cathodic arc to protect themetal layer from oxidation. For the sake of comparison, a 50 Å layer oftantalum oxide (TaO) was also deposited on samples. Sixty (60) examplesof each sample were prepared. The examples were thermally annealed at400° C. for 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, or 48 hours(given in Table 7 below). Critical dimension scanning electronmicroscopy (CD-SEM) was then used to evaluate whether or not the pegrecessed from the ABS surface. Table 1 shows the samples and theirfailure rate as a percentage.

Failure rates for the various structures are show in Table 7 below.

TABLE 7 Time of Anneal 20 1 3 6 12 24 48 Layers mins. hour hours hourshours hours hours 50 Å TaO 100 100 (98.6% failure when annealing at 300°C. for 3 hours) 25 Å Ir/ 0 0 0 0 1.82 9.09 20 Å Cr/ 20 Å DLC

FIG. 6A shows a scanning electron microscope (SEM) image of one of the25 Å Ir/20 Å Cr/20 Å DLC samples annealed for about 48 hours. FIG. 6Bshows a SEM of one of the TaO layers annealed at 300° C. for 3 hours forthe sake of comparison.

All scientific and technical terms used herein have meanings commonlyused in the art unless otherwise specified. The definitions providedherein are to facilitate understanding of certain terms used frequentlyherein and are not meant to limit the scope of the present disclosure.

As used in this specification and the appended claims, “top” and“bottom” (or other terms like “upper” and “lower”) are utilized strictlyfor relative descriptions and do not imply any overall orientation ofthe article in which the described element is located.

As used in this specification and the appended claims, the singularforms “a”, “an”, and “the” encompass embodiments having pluralreferents, unless the content clearly dictates otherwise.

As used in this specification and the appended claims, the term “or” isgenerally employed in its sense including “and/or” unless the contentclearly dictates otherwise. The term “and/or” means one or all of thelisted elements or a combination of any two or more of the listedelements.

As used herein, “have”, “having”, “include”, “including”, “comprise”,“comprising” or the like are used in their open ended sense, andgenerally mean “including, but not limited to”. It will be understoodthat “consisting essentially of”, “consisting of”, and the like aresubsumed in “comprising” and the like. For example, a conductive tracethat “comprises” silver may be a conductive trace that “consists of”silver or that “consists essentially of” silver.

As used herein, “consisting essentially of,” as it relates to acomposition, apparatus, system, method or the like, means that thecomponents of the composition, apparatus, system, method or the like arelimited to the enumerated components and any other components that donot materially affect the basic and novel characteristic(s) of thecomposition, apparatus, system, method or the like.

The words “preferred” and “preferably” refer to embodiments that mayafford certain benefits, under certain circumstances. However, otherembodiments may also be preferred, under the same or othercircumstances. Furthermore, the recitation of one or more preferredembodiments does not imply that other embodiments are not useful, and isnot intended to exclude other embodiments from the scope of thedisclosure, including the claims.

Also herein, the recitations of numerical ranges by endpoints includeall numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2,2.75, 3, 3.80, 4, 5, etc. or 10 or less includes 10, 9.4, 7.6, 5, 4.3,2.9, 1.62, 0.3, etc.). Where a range of values is “up to” a particularvalue, that value is included within the range.

Use of “first,” “second,” etc. in the description above and the claimsthat follow is not intended to necessarily indicate that the enumeratednumber of objects are present. For example, a “second” substrate ismerely intended to differentiate from another infusion device (such as a“first” substrate). Use of “first,” “second,” etc. in the descriptionabove and the claims that follow is also not necessarily intended toindicate that one comes earlier in time than the other.

Thus, embodiments of devices including at least one adhesion layer andmethods of forming adhesion layers are disclosed. The implementationsdescribed above and other implementations are within the scope of thefollowing claims. One skilled in the art will appreciate that thepresent disclosure can be practiced with embodiments other than thosedisclosed. The disclosed embodiments are presented for purposes ofillustration and not limitation.

What is claimed is:
 1. A device comprising: a near field transducer(NFT), the NFT having a disc and a peg, and the peg having an airbearing surface thereof; and at least one adhesion layer positioned onat least the air bearing surface of the peg, the adhesion layercomprising one or more of platinum (Pt), iridium (Ir), ruthenium (Ru),rhodium (Rh), palladium (Pd), yttrium (Y), chromium (Cr), nickel (Ni),and scandium (Sc).
 2. The device according to claim 1, wherein the NFTcomprises gold or an alloy thereof.
 3. The device according to claim 1further comprising an adhesion layer on a surface of the peg that isalong an axis having a core of a waveguide and a write pole.
 4. Thedevice according to claim 3, wherein the adhesion layer is locatedadjacent the core of the waveguide.
 5. The device according to claim 3further comprising at least one additional adhesion layer located on asurface of the peg that is perpendicular to the axis having the core andthe write pole.
 6. The device according to claim 1, wherein the peg hasfive surfaces thereof and all five surfaces of the peg have an adhesionlayer thereon.
 7. The device according to claim 1, wherein the at leastone adhesion layer has a thickness from about 0.1 nm to about 100 nm. 8.The device according to claim 1, wherein the at least one adhesion layerhas a thickness from about 0.2 nm to about 5 nm.
 9. The device accordingto claim 1, wherein the at least one adhesion layer has a thickness from0.2 nm to 3.5 nm.
 10. A device comprising: an energy source; a nearfield transducer (NFT) configured to receive energy from the energysource, the NFT having a disc and a peg, and the peg having an airbearing surface; and at least one adhesion layer positioned on at leastthe air bearing surface of the peg, the adhesion layer comprising one ormore of platinum (Pt), iridium (Ir), ruthenium (Ru), rhodium (Rh),palladium (Pd), yttrium (Y), chromium (Cr), nickel (Ni), and scandium(Sc).
 11. The device according to claim 10, wherein the energy sourcecomprises a laser.
 12. The device according to claim 10 furthercomprising a waveguide, the waveguide configured to receive the energyfrom the energy source and couple it into the NFT.
 13. The deviceaccording to claim 12 further comprising at least one additionaladhesion layer located on a surface of the peg that is along an axishaving the core of the waveguide.
 14. The device according to claim 10,wherein the at least one adhesion layer comprises tantalum oxide,titanium oxide, tin oxide, indium oxide, or combinations thereof.
 15. Amethod of forming a device comprising: forming a first material to beadhered to; forming a NFT; and forming an adhesion layer comprising oneor more of platinum (Pt), iridium (Ir), ruthenium (Ru), rhodium (Rh),palladium (Pd), yttrium (Y), chromium (Cr), nickel (Ni), and scandium(Sc), wherein the adhesion layer is deposited between the first materialto be adhered to and the NFT.
 16. The method according to claim 15,wherein the first material to be adhered to is an underlying dielectricmaterial and the underlying dielectric material is formed before theadhesion layer material and the adhesion layer material is formed beforethe NFT.
 17. The method according to claim 15, wherein the firstmaterial to be adhered to is an overlying dielectric material and theNFT is formed before the adhesion layer material and the adhesion layermaterial is formed before the overlying dielectric material.
 18. Themethod according to claim 18, wherein the first material to be adheredto is an underlying dielectric material and the underlying dielectricmaterial is formed before the adhesion layer material and the adhesionlayer material is formed before the NFT, and wherein forming the NFTcomprises depositing NFT material and trimming the deposited NFTmaterial and at least some of the deposited adhesion layer material whenforming the NFT.
 19. The method according to claim 18 further comprisingdepositing additional adhesion layer material on the NFT after trimming.20. The method according to claim 19 further comprising depositing anoverlying dielectric layer on the additionally deposited adhesion layermaterial.